RE: [linrad] : Volume control in filter window ( RF )

[Leif Asbrink <leif.asbrink@xxxxxxxxxxxxxxxxxxxx]

Hi Rein and All,

> It probably really does not matter, but this control scale shows 72 scale
> divisions here. ( ver lin00-54 ). It does not seem to be a function of 
> window scaling.

The volume control is 0 to 100%. That is how I like to think of it;)

At the top, the noise floor will saturate the output. At the bottom
a signal that saturated the A/D converter will be very weak.

The dB scale is for the graphical display only. There may be good
reasons to expand or compress the Y-scale but it would not be a good
idea to change the audio volume simultaneously.

> What are the bfo frequency steps, 256 Hz or so?
Like everything else, the step size is one pixel. What it means 
in Hz depends on the scale you selected. If you select a 25 Hz 
wide filter you would typically display 250Hz on the 
screen with 8 frequency bins across the 25 Hz and 5 pixels per 
frequency bin. The baseband window would be a few hundred pixels
wide and you have 0.625 Hz increments for the upper BFO control.
Now that is useless because the range is only +/- 125Hz or so.
The middle BFO control will have an increment of 6.25 Hz per
pixel and you can easily set a suitable tone for narrow CW 
reception.

73

Leif / SM5BSZ



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